CN104149724B - Crushing force course active control device for thin-walled cylinder energy absorption structure - Google Patents

Abstract

The invention discloses a crushing force course active control device for a thin-walled cylinder energy absorption structure. In the length L direction of a thin-walled cylinder, annular grooves with depths ranging from h0 to h0-nt are gradually formed inside and outside the cylinder, and the interval of the grooves is W; by setup of the depth h0 and the groove interval W, amplitude and pulse width of a buckling initial crushing force can be controlled, and by setup of the depth variation t of different grooves, variation of a buckling crushing force can be adjusted precisely. By the aid of the annular grooves in different size along the length direction of the thin-walled cylinder, the buckling mode and plastic hinge forming position of the thin-walled cylinder can be effectively controlled; by control of depth variation, widths, intervals and the like of the grooves, a buckling crushing force course can be effectively controlled.

Description

A kind of crushing force course active control device of thin cylinder endergonic structure

Technical field

The present invention relates to collision energy-absorbing safety protection field is and in particular to a kind of crushing force of thin cylinder endergonic structure is gone through Journey active control device.

Background technology

For the vehicles such as automobile, bullet train, impingement phenomenon always is of crucial importance and can not avoid Problem.In recent years, increase sharply with automobile and bullet train quantity and travel speed continuous improvement so that collision problem More and more prominent, the collision accident increasing sharply can cause great personal injury and property loss, Impact Resisting Capability become automobile, The problem of overriding concern during the structure designs such as bullet train.

People notice that thin cylinder typically has stable progressive failure model under axial compression very early, are bent by plasticity Bent energy absorption.Thin cylinder is traditional buffering energy-absorbing structure, is also one of most widely used buffering energy-absorbing structure, even if As beer fills, lightweight construction is subject to the effect of axial impact loading also can absorb considerable energy.Thin cylinder is ground Study carefully the metal tube more than other cross sectional shapes, thin cylinder is also widely applied in energy-absorbing system, is on the one hand because Deformation pattern stable thus controllably energy absorption, be on the other hand because in the vehicles containing substantial amounts of thin cylinder knot Structure, thus ensure not increasing extra weight in crash-worthiness designs.Thin-wall construction is subject to the dynamic elasto-plaslicity of axial impact loading Flexing is a very complicated phenomenon, and the joint effect of geometric parameter, load condition and material character according to housing has three kinds The Failure Model of type, that is, (before big radial displacement, cylinder produces wrinkle along whole length direction to dynamic plastic buckling Folding), (in the case of low velocity impact, similar to static(al) situation, fold is from the beginning of one end to its deformation process to dynamic progressive buckling Formed and gradually develop to the other end, this kind of pattern is preferable energy-absorbing modes) and Euler's bending.

For dynamic progressive buckling, forefathers have done substantial amounts of theoretical, experiment and number crunching.Conventional theoretical research Concentrate in the prediction of the average crushing force of flexing, and collapse energy-absorption process control is lacked theoretical.Thin cylinder is subject to itself Physical dimension, material behavior, extraneous load, the combined influence of boundary condition, buckling pattern often cannot accurately be estimated, axial symmetry The plastic hinge forming process of annulus pattern and nonaxisymmetrical diamond pattern, difference is very big in energy absorption ability, this is to pressure It is far-reaching for the most important parameter of this energy absorption device of course, therefore traditional thin cylinder endergonic structure cannot be real The accurate prediction of existing Collapse of Concrete and control.

Content of the invention

In consideration of it, it is an object of the invention to provide a kind of crushing force course active control device, above-mentioned existing in order to solve Technical problem present in technology.

The invention provides a kind of crushing force course active control device of thin cylinder endergonic structure, wherein, along thin Wall drum length L direction, inside and outside in cylinder progressively arranges different depth h₀To h₀The annular groove of-nt, between groove Away from for H；By arranging different depth h₀With flute pitch H, control amplitude and the pulsewidth of the initial crushing force of flexing, setting is different Depth of groove change t, the change of accurate adjustment flexing crushing force.

Further, the derivation formula of n-th section of flexing crushing force Fn is：

Further, described device can apply to automobile, the optimization design of bullet train energy absorption device, and aircraft, Optimization design of soft spacecraft landing device etc..

The present invention compared with prior art has clear advantage and beneficial effect.Specifically, the present invention is using thin Various sizes of annular groove along its length, the buckling pattern of effective control thin cylinder, plastic hinge shape are arranged on wall cylinder Become position.By controlling groove depth change and groove width, separation etc. of groove, can be with effective control flexing crushing force course.Meanwhile, Give theoretical prediction formula for the thin cylinder impact crushing force course that this kind of method obtains, by adjusting the ginseng of defect Number, the Collapse of Concrete that can carry out meeting different crushing force courses controls.

Brief description

Fig. 1 is the defect arrangement schematic diagram of thin cylinder crushing force course active control.

Fig. 2 is that groove defect forms the schematic diagram of active control to plastic hinge.

Fig. 3 is the crushing force course curve synoptic diagram of typically complete cylinder.

Fig. 4 is the crushing force course curve synoptic diagram of typical active control cylinder.

Wherein：D：Drum diameter, L：Drum length, h：Wall thickness of cylinder, h₀:The depth of first groove, t：Depth of groove Change, H：Flute pitch, W：Recess width.

Specific embodiment

Crushing force course active control device to the thin cylinder endergonic structure that the present invention provides below in conjunction with the accompanying drawings Specific embodiment elaborates.

As shown in figure 1, being directed to thin cylinder flexing energy absorption device, along thin cylinder length L direction, in the inside of cylinder Progressively arrange different depth h with outside₀To h₀The annular groove of-nt, the spacing of groove is H.Because groove wall thickness is relatively thin, then For comparing complete cylinder, groove is easier flexing.Because the depth along drum length direction groove is different, then can essence Really control flexing starting point in upper end groove the deepest, and the progressively little local development of depth of groove downwards.For each The formation of individual flexing fold, as shown in Fig. 2 by the plastic bending of three plastic hinges and the stretching of material between yield line and pressure Contract and to absorb impact kinetic energy.By arranging different depth h₀With flute pitch H, the amplitude of the initial crushing force of flexing can be controlled And pulsewidth.Change t by arranging different depths of groove, can be with the change of accurate adjustment flexing crushing force.By said method, The active control of the crushing force course to thin cylinder Impact Buckling energy absorption device can be accomplished, may apply to automobile, at a high speed The optimization design of train energy absorption device, aircraft, optimization design of soft spacecraft landing device etc..

The above-mentioned configuration for design, make use of conservation of energy principle, load is to cylinder work done by three plastic hinges Between the plastic bending of line and plastic hinge, the elongation of material circumference is dissipated, and derives and obtains control theory formula：Wherein S is conquassation position Move, the interval being in for conquassation displacement, n-th section of flexing crushing force F can be predicted_n.

It can be seen in figure 3 that typically the crushing force course curve of complete cylinder is periodically to shake, due to wall thickness, directly Footpath is constant along its length, and its corresponding crushing force of each fold is consistent substantially, and that is, flexing whole process is consistent substantially Average crushing force.

Figure 4, it is seen that the crushing force of typical active control cylinder incrementally increases with conquassation displacement, and each pleat The all available theoretical formula of the average crushing force of wrinkle reaches good prediction, and this is consistent with the control effect of anticipation, by this Kind of Active Control Method, can accurately predict the behavior in thin cylinder flexing each stage, and can each fold of Accurate Prediction flat All crushing forces.By changing the arrangement of groove defect, can complete thin cylinder endergonic structure difference crushing force course needs The design asked.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for the skill of this area For art personnel, the present invention can have various modifications and variations.All within the spirit and principles in the present invention, made any repair Change, equivalent, improvement etc., should be included within the scope of the present invention.

Claims (3)

1. the crushing force course active control device of a kind of thin cylinder endergonic structure, wherein, along thin cylinder length L side To inside and outside in cylinder progressively arranges different depth h₀To h₀The annular groove of-nt, the spacing of groove is H；By setting Put different depth h₀With flute pitch H, control amplitude and the pulsewidth of the initial crushing force of flexing, different depths of groove are set and become Change t, the change of accurate adjustment flexing crushing force.

2. device according to claim 1 is it is characterised in that the derivation formula of n-th section of flexing crushing force Fn is：

$\begin{array}{c}{F}_n=\frac{E_n}{2(H+W)}=\left(\frac{h^2+h_0^2+4{(n-1)}^2{t}^2-4{\mathrm{nth}}_0+4{\mathrm{nt}}^2-2t^2-2{\mathrm{hh}}_0+4nht-2ht+2h_{0}t}{\sqrt{3}}\mathrm{\π}Y\right(\frac{\mathrm{\π}}{2}D-(H\\ +W\left)\right)+\frac{\mathrm{\π}Y{(h-h_0+2nt-t)}^2}{\sqrt{3}}(\frac{\mathrm{\π}}{2}D+(H+W))+\mathrm{\π}(2h-2h_0+4nt-2t)Y(\frac{W^2}{2}+HW)+{\mathrm{\πhYH}}^2)/2(H+W)\end{array}.$

3. device according to claim 1 and 2 is it is characterised in that described device can apply to automobile, bullet train energy-absorbing The optimization design of device, and the optimization design of aircraft, soft spacecraft landing device.